Process for the preparation of anthraquinone imides

Abstract

In the preparation of anthraquinone imides by condensing a vattable anthraquinone compound which contains at least one primary amino group with an aromatic halogen compound, in an organic solvent and at elevated temperature, it is advantageous first to heat the organic solvent to the reaction temperature and then, at this temperature, to add the educts to the solvent.

What is claimed is: 
     
       1. In a process for the preparation of an anthraquinone imide by condensing a vattable anthraquinone compound which contains at least one primary amino group with a halogenated anthraquinone, benzanthrone, anthanthrone, pyranthrone, dibenzanthrone, phthaloylacridone, flavanthrone, dibenzpyrenequinone or isoviolanthrone, which aromatic halogen compounds are unsubstituted or further substituted by halogen, alkyl, alkoxy, acylamino or fused benzene rings, in an non-aqueous inert organic solvent and in the presence of a base and a copper catalyst, the improvement of which comprises heating a portion of the inert organic solvent to the reaction temperature which is in the range of 140° to 250° C. and, at this temperature, adding the reactants in the form of a suspension or solution in such a manner that the reaction temperature can be maintained, the reactants thereby being heated to the reaction temperature within less than 10 minutes, and holding at the reaction temperature until the condensation reaction is complete. 
     
     
       2. A process according to claim 1, which comprises heating the reactants in the organic solvent, to the reaction temperature within less than 1 minute. 
     
     
       3. A process according to claim 2, which comprises heating the reactants, in the organic solvent, to the reaction temperature within less than 10 seconds. 
     
     
       4. A process according to claim 1, wherein the reaction temperature is in the range from 180° to 220 ° C. 
     
     
       5. A process according to claim 4, wherein the reaction temperature is in the range from 195° to 215° C. 
     
     
       6. A process according to claim 1, which comprises adding 5 to 30% by weight of the base and the copper catalyst to the solvent, which has been heated to the reaction temperature, and adding the remainder together with the reactants. 
     
     
       7. A process according to claim 1, wherein the vattable anthraquinone compound which contains at least one primary amino group is selected from 1-aminoanthraquinone, 1,4-diaminoanthraquinone, 1,5-diaminoanthraquinone, 1-amino-4-benzoylaminoanthraquinone, 1-amino-5-benzoylamino-anthraquinone or aminoviolanthrone. 
     
     
       8. A process according to claim 1, wherein the aromatic halogen compound is selected from chlorinated or brominated anthraquinone, benzanthrone, anthanthrone, pyranthrone or dibenzanthrone. 
     
     
       9. A process according to claim 1, wherein the copper catalyst is copper or copper(I) chloride.